The present invention relates to a ballistic laminate. It finds particular application in conjunction with a ballistic laminate that offers both ballistic and flame retardant properties and will be described with particular reference thereto. It will be appreciated, however, that the invention is also amenable to other applications.
Ballistic resistant body armor and vehicle armor are made from either woven fabrics or unidirectional fabrics comprising high performance fibers such as ultra-high-molecular-weight-polyethylene (UHMWPE) fibers, aramid fibers, and glass fibers, etc. Unidirectional fiber reinforced composite where fibers are encapsulated in a polymeric matrix materials generally has better ballistic resistance than traditional woven fabrics.
Various unidirectional composite constructions are currently used for formation of soft and hard armors in ballistic protection applications. Some composite constructions use high performance fibers such as UHMWPE fibers in matrix materials. However, some high performance fibers such as UHMWPE fibers are flammable when exposed to fire and heat. There is a growing demand for fire resistance armors.
One conventional composite construction use a layer-by-layer hybrid composite construction (i.e., one or more layers comprising flame resistant fibers and one or more layers comprising flammable fiber to improve the flame resistance of the composite). One multilayer composite design includes one or more first layers of flammable fibers in a matrix and at least one second layer adjacent to the first layer. The second matrix includes a fire retardant material. The second matrix is different than the first matrix.
Another conventional composite construction includes at least one layer of UHMWPE fibers or aramid fibers in a matrix and at least one fire retardant layer. The fire retardant layer includes a fire retardant agent that absorbs heat when exposed to fire and heat in a matrix. The matrix includes one or more relatively high chart yield resins that results in better flame resistant performance.
Another conventional composite construction includes a molded ballistic panel for use in aircraft and land vehicles for structural, ballistic, and fire resistant performance. The molded panel is formed by inserting a honeycomb between panels including non-woven high performance fiber layers and one or more fire resistant fiber layers.
U.S. Pat. No. 7,288,307 to Bhatnagar, et al. discloses hybrid laminated unidirectional fiber sheets produced from continuous roll of unidirectional prepregs, having application for impact absorption, ballistic resistance, and penetration resistance. The laminated unidirectional fiber sheets include two or more types of unidirectional fibers with different composition in a matrix. The two or more types of fibers are arranged in a side by side position. The periodic distance between fibers that have the same composition is not greater than 9 mm. However, neither distinguishes flame resistant fibers compared with flammable fibers nor gives any description on hybrid fiber-by-fiber composite constructions and/or fiber arrangements that improve the flame resistance performance of a composite.
The present invention provides a new and improved apparatus and method which addresses the above-referenced problems.